The invention is related to a wireless mobile communication system, and particularly, to providing a transmit output controlling circuit and method for controlling a transmit output level corresponding to a receive sensitivity between a master and a slave, alternatively.
In other words, the transmit output controlling circuit and method is as follows: the slave transmits a predetermined data corresponding to the receive sensitivity together with the data information transmitted from the master, and the master controls the transmit output level catching up with the receive sensitivity of the slave, thereby reducing the power consumption in a local communication.
A conventional wireless mobile communication system using FRS transmits data information at a maximum transmit output irrelevant to a local or remote communication. If the wireless mobile communication system receives the data information in a short distance, its output is unnecessarily strong. It has problems in taking a bad effect on another communication and consuming the power over what is required.
A conventional wireless mobile communication method is as follows: a same frequency channel is set between a master and a slave for the communication. As the master transmits a predetermined information, the slave receives the information from the master and measures the receive sensitivity. If the receive sensitivity is excessively strong, the slave lowers its transmit output. But, when the master receives the information from the slave, the receive sensitivity is relatively lower, because the transmit output of the slave was already reduced. It has a problem in that the transmit output of the master cannot be controlled.
Accordingly, in order to resolve these problems, a main object of the invention is to provide a transmit output controlling circuit and method of a wireless mobile communication system for controlling a transmit output level according to a receive sensitivity of a counterpart to be communicated.
The other object of the invention is to provide a transmit output controlling circuit and method of a wireless mobile communication system for controlling a transmit output level according to a communication distance, thereby reducing the power consumption in a local communication.
According to the invention, a transmit output controlling circuit of a wireless mobile communication system comprises a demodulating portion for detecting an immediate frequency of a receive information induced through an antenna and passing through a duplexer portion; a receive sensitivity measuring portion for detecting a receive sensitivity level of the immediate frequency signal detected by the demodulating portion; a controller for receiving data from the demodulating portion and outputting a receive sensitivity data, a timing control signal and a transmit power control signal; a transmit signal control a receive sensitivity data into a transmit signal according to the receive sensitivity data and the timing control signal from the controller; a transmit output amplifying portion for amplifying the transmit signal from the transmit signal control; and a transmit power control for controlling an amplification factor of the transmit output amplifying portion according to the control signal from the controller.
A transmit output controlling method of a wireless mobile communication system comprises steps of judging whether a receive signal exists at a waiting mode of the communication system or not, measuring a receive sensitivity if the receive signal is inputted at the receive signal existence judging step; judging whether the sensitivity level measured is over a setting value; mixing a responding transmit data into the receive sensitivity and then transmitting the mixed data; forcing another communication system in a receive mode to detect a receive data; judging whether a sensitivity measuring data exists in the data detected at the receive data detecting step; controlling a transmit output level according to the sensitivity measuring data detected at the sensitivity measuring data existence judging step and transmitting a data for the communication.